Substrate processing apparatus and processing method of substrate processing apparatus

ABSTRACT

Imaging can be performed well even when an imaging device is disposed at a position facing a peripheral portion of a substrate. A substrate processing apparatus  16  which performs a processing of removing a film on a peripheral portion of a substrate W includes a rotating/holding unit  210  configured to hold and rotate the substrate; a first processing liquid supply unit  250 A configured to supply a first processing liquid for removing the film onto the peripheral portion of the substrate while the substrate is being rotated in a first rotational direction R 1  by the rotating/holding unit; and an imaging unit  270  provided at a position in front of an arrival region  902  of the first processing liquid on the substrate with respect to the first rotational direction R 1 , and configured to image the peripheral portion of the substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Japanese Patent Application No.2016-068187 filed on Mar. 30, 2016, the entire disclosures of which areincorporated herein by reference.

TECHNICAL FIELD

The embodiments described herein pertain generally to a substrateprocessing apparatus configured to process a substrate such as asemiconductor wafer with a processing liquid.

BACKGROUND

There is known a substrate processing system equipped with asingle-sheet type substrate processing apparatus. As one of this kind ofsystem, there is a substrate processing apparatus having a function ofremoving a film on a peripheral portion of a substrate by supplying aprocessing liquid onto the peripheral portion of the substrate from anozzle while holding the substrate having a film formed on a surfacethereof and rotating the substrate around a vertical axis. In PatentDocument 1, an imaging unit is provided in the substrate processingsystem, and an image of the peripheral portion of the substrateprocessed by the substrate processing apparatus is obtained. Based onthe image, it is determined whether the film on the peripheral portionof the substrate is appropriately removed.

Patent Document 1: Japanese Patent Laid-open Publication No. 2013-168429

In case that the imaging unit is disposed at a position facing theperipheral portion of the substrate in the state that the substrate isheld by the substrate processing apparatus, a liquid may adhere to or becoated on the imaging unit while processing the substrate with theprocessing liquid, so that the successful image cannot be obtained. ThePatent Document 1 does not mention any solution to such a problem.

SUMMARY

In view of the foregoing, exemplary embodiments can perform successfulimaging even when an imaging device is disposed at a position facing aperipheral portion of a substrate.

In an exemplary embodiment, a substrate processing apparatus whichperforms a processing of removing a film on a peripheral portion of asubstrate includes a rotating/holding unit configured to hold and rotatethe substrate; a first processing liquid supply unit configured tosupply a first processing liquid for removing the film onto theperipheral portion of the substrate while the substrate is being rotatedin a first rotational direction by the rotating/holding unit; and animaging unit provided at a position in front of an arrival region of thefirst processing liquid on the substrate with respect to the firstrotational direction, and configured to image the peripheral portion ofthe substrate.

According to the exemplary embodiments, it is possible to achieve aneffect that the successful imaging can be performed even when theimaging device is disposed at the position facing the peripheral portionof the substrate.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

In the detailed description that follows, embodiments are described asillustrations only since various changes and modifications will becomeapparent to those skilled in the art from the following detaileddescription. The use of the same reference numbers in different figuresindicates similar or identical items.

FIG. 1 is a plan view illustrating an outline of a substrate processingsystem according to an exemplary embodiment;

FIG. 2 is a vertical side view of a processing unit according to theexemplary embodiment;

FIG. 3 is a plan view illustrating a cover member of the processingunit, an elevating device therefor and processing liquid supply units;

FIG. 4A and FIG. 4B are enlarged cross sectional views illustrating thevicinity of a peripheral edge of a wafer on the right side of FIG. 2 indetail;

FIG. 5 is a cross sectional view illustrating a detailed configurationof an imaging device;

FIG. 6 is a diagram illustrating a schematic configuration of ameasurement processing system according to the exemplary embodiment;

FIG. 7 is a diagram showing an overall flow of a substrate processingand a measurement processing performed by the substrate processingsystem and the measurement processing system according to a firstexemplary embodiment;

FIG. 8 is a diagram for specifically describing a chemical liquidprocessing of the overall flow according to the first exemplaryembodiment;

FIG. 9A and FIG. 9B are diagrams for describing a relationship between aplacement of the imaging device and a liquid state on the wafer W in thechemical liquid processing according to the present exemplaryembodiment;

FIG. 10 is a diagram illustrating an angle of view of the imaging devicewith respect to the wafer W;

FIG. 11 is a diagram illustrating an arrangement relationship of theimaging device, the processing unit and the wafer W;

FIG. 12A and FIG. 12B are flowcharts for describing an operation ofmeasuring a cut width and an eccentric amount;

FIG. 13 is a schematic diagram of a second image obtained under a secondimaging condition;

FIG. 14 is a schematic diagram of a first image obtained under a firstimaging condition;

FIG. 15 illustrates an eccentric state of the wafer W with respect to aholding unit;

FIG. 16 is a graph showing a measurement result of the cut width withrespect to a rotation angle of the wafer W;

FIG. 17 is a diagram illustrating an example of a display screen showingmeasurement result information displayed on a display device;

FIG. 18A and FIG. 18B are diagrams for describing a configuration of aholding position adjusting device;

FIG. 19 is a diagram for describing an overall flow according to asecond exemplary embodiment;

FIG. 20 is a flowchart for describing a holding position adjustingprocessing according to the second exemplary embodiment;

FIG. 21A to FIG. 21H are diagrams for describing an operation of theholding position adjusting device;

FIG. 22A and FIG. 22B are diagrams for describing an image processingrecipe;

FIG. 23 is a flowchart for describing an imaging setting processingaccording to a third exemplary embodiment;

FIG. 24 is a diagram showing an information list of measurementprocessing results;

FIG. 25A and FIG. 25B are diagrams for describing a method of analyzingand utilizing the measurement processing results;

FIG. 26 is a diagram for describing an overall flow according to afourth exemplary embodiment;

FIG. 27 is a flowchart for describing an analyzing processing of ameasurement processing result according to the fourth exemplaryembodiment;

FIG. 28 is a plan view illustrating a cover member of a processing unit,an elevating device therefor and a processing liquid supply unitaccording to a fifth exemplary embodiment;

FIG. 29A and FIG. 29B are diagrams for describing a positionalrelationship among an imaging device, a wafer W and a liquid on thewafer W;

FIG. 30 is a diagram for describing an arrangement relationship of theimaging device, the processing unit and the wafer W in an imaging regionand describing a liquid-existing state of a chemical liquid or a rinseliquid; and

FIG. 31 is a flowchart for describing a chemical liquid processingperformed along with a recording according to the fifth exemplaryembodiment.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part of the description. In thedrawings, similar symbols typically identify similar components, unlesscontext dictates otherwise. Furthermore, unless otherwise noted, thedescription of each successive drawing may reference features from oneor more of the previous drawings to provide clearer context and a moresubstantive explanation of the current exemplary embodiment. Still, theexemplary embodiments described in the detailed description, drawings,and claims are not meant to be limiting. Other embodiments may beutilized, and other changes may be made, without departing from thespirit or scope of the subject matter presented herein. It will bereadily understood that the aspects of the present disclosure, asgenerally described herein and illustrated in the drawings, may bearranged, substituted, combined, separated, and designed in a widevariety of different configurations, all of which are explicitlycontemplated herein.

In the present exemplary embodiments, a configuration of a substrateprocessing system, a configuration of a measurement processing systemand operations thereof will be mainly described.

FIG. 1 is a plan view illustrating an outline of a substrate processingsystem provided with a processing unit according to an exemplaryembodiment of the present disclosure. In the following, in order toclarify positional relationships, the X-axis, Y-axis and Z-axis whichare orthogonal to each other will be defined. The positive Z-axisdirection will be regarded as a vertically upward direction.

As illustrated in FIG. 1, a substrate processing system 1 includes acarry-in/out station 2 and a processing station 3. The carry-in/outstation 2 and the processing station 3 are provided adjacent to eachother.

The carry-in/out station 2 is provided with a carrier placing section 11and a transfer section 12. In the carrier placing section 11, aplurality of carriers C is placed to accommodate a plurality ofsubstrates (semiconductor wafers in the present exemplary embodiment)(hereinafter, referred to as “wafers W”) horizontally.

The transfer section 12 is provided adjacent to the carrier placingsection 11, and provided with a substrate transfer device 13 and adelivery unit 14. The substrate transfer device 13 is provided with awafer holding mechanism configured to hold the wafer W. Further, thesubstrate transfer device 13 is movable horizontally and vertically andpivotable around a vertical axis, and transfers the wafers W between thecarriers C and the delivery unit 14 by using the wafer holdingmechanism.

The processing station 3 is provided adjacent to the transfer section12. The processing station 3 is provided with a transfer section 15 anda plurality of processing units 16. The plurality of processing units 16is arranged at both sides of the transfer section 15.

The transfer section 15 is provided with a substrate transfer device 17therein. The substrate transfer device 17 is provided with a waferholding mechanism configured to hold the wafer W. Further, the substratetransfer device 17 is movable horizontally and vertically and pivotablearound a vertical axis. The substrate transfer device 17 transfers thewafers W between the delivery unit 14 and the processing units 16 byusing the wafer holding mechanism.

The processing units 16 perform a predetermined substrate processing onthe wafers W transferred by the substrate transfer device 17.

Further, the substrate processing system 1 is provided with a controldevice 4. The control device 4 is, for example, a computer, and includesa control unit 18 and a storage unit 19. The storage unit 19 stores aprogram that controls various processings performed in the substrateprocessing system 1. The control unit 18 controls the operations of thesubstrate processing system 1 by reading and executing the programstored in the storage unit 19.

Further, the program may be recorded in a computer-readable recordingmedium, and installed from the recording medium to the storage unit 19of the control device 4. The computer-readable recording medium may be,for example, a hard disc (HD), a flexible disc (FD), a compact disc(CD), a magnet optical disc (MO), or a memory card.

In the substrate processing system 1 configured as described above, thesubstrate transfer device 13 of the carry-in/out station 2 first takesout a wafer W from a carrier C placed in the carrier placing section 11,and then places the taken wafer W on the delivery unit 14. The wafer Wplaced on the delivery unit 14 is taken out from the delivery unit 14 bythe substrate transfer device 17 of the processing station 3 and carriedinto a processing unit 16.

The wafer W carried into the processing unit 16 is processed by theprocessing unit 16, and then, carried out from the processing unit 16and placed on the delivery unit 14 by the substrate transfer device 17.After the processing of placing the wafer W on the delivery unit 14, thewafer W returns to the carrier C of the carrier placing section 11 bythe substrate transfer device 13.

Now, a detailed configuration of the processing unit 16 according to thepresent exemplary embodiment will be explained. The processing unit 16corresponds to a substrate processing apparatus of the presentdisclosure. Further, the processing unit 16 is configured to perform asubstrate processing of supplying a chemical liquid onto a front surfaceof a wafer W as a circular substrate on which a semiconductor device isto be formed and removing an unnecessary film formed on a peripheralportion of the wafer W.

As shown in FIG. 2 and FIG. 3, the processing unit 16 includes a waferholding unit 210 configured to hold the wafer W horizontally and allowto be pivotable around a vertical axis; a cup body 220 surrounding thewafer W held by the wafer holding unit 210 and configured to receive aprocessing liquid dispersed from the wafer W; a ring-shaped cover member230 configured to cover a peripheral portion of a top surface of thewafer W held by the wafer holding unit 210; an elevating device (movingdevice) 240 configured to move the cover member 230 up and down; andprocessing liquid supply units 250A and 250B each configured to supply aprocessing fluid to the wafer W held by the wafer holding unit 210.

The aforementioned constituent components of the processing unit 16,that is, the cup body 220, the wafer holding unit 210, the cover member230, and so forth are accommodated in a single housing 260. A clean airinlet unit 261 configured to introduce clean air from the outside isprovided at a ceiling portion of the housing 260. Further, an exhaustopening 262 for exhausting an atmosphere within the housing 260 isprovided in the vicinity of a bottom surface of the housing 260.Accordingly, a downflow of the clean air flowing from an upper portionof the housing 260 to a lower portion thereof is formed within thehousing 260. A carry-in/out opening 264 which is opened or closed by ashutter 263 is provided at one sidewall of the housing 260. A transferarm of a non-illustrated wafer transfer device provided at an outside ofthe housing 260 is capable of passing through the carry-in/out opening264 while holding the wafer W. The wafer holding unit 210 is configuredas a circular plate-shaped vacuum chuck, and a top surface of the waferholding unit 210 is configured as a wafer attraction surface. The waferholding unit 210 can be rotated at a required speed by a non-illustratedrotational driving device. The wafer holding unit 210 corresponds to arotating/holding unit of the present disclosure.

As shown in FIG. 2, the cup body 220 is a circular ring-shaped memberhaving a bottom and is provided to surround an outer circumference ofthe wafer holding unit 210. The cub body 220 serves to receive andcollect a chemical liquid scattered from the wafer W after supplied tothe wafer W and is configured to drain the received chemical liquid tothe outside.

A small gap (for example, having a height of 2 mm to 3 mm) is formedbetween a bottom surface of the wafer W held by the wafer holding unit210 and a top surface 212 of an inner circumferential portion 211 of thecup body 220 facing the bottom surface of the wafer W. The top surface212 facing the wafer W is provided with two gas discharge openings 213and 214. The two gas discharge openings 213 and 214 are continuouslyextended along a large-diameter circumference and a small-diametercircumference which are concentric, respectively. The gas dischargeopenings 213 and 214 discharge a N₂ gas (heated N₂ gas) toward thebottom surface of the wafer W diagonally upwards and outwards in theradial direction. The N₂ gas is supplied into a circular ring-shaped gasdiffusion space 215 from a non-illustrated gas inlet line formed withinthe inner circumferential portion 211 of the cup body 220. Then, the N₂gas is diffused and flown in the circumferential direction while beingheated within the gas diffusion space 215 and is discharged from the gasdischarge openings 213 and 214.

A drain path 216 and an exhaust path 217 are connected to an outercircumference side of the cup body 220. A ring-shaped guide plate 218 isextended outwards in the radial direction from an outer peripheralportion (a position under a peripheral edge of the wafer W) of the innercircumferential portion 211 of the cup body 220. Further, acircumferential outer wall 219 is provided at the outer circumferenceside of the cup body 220. The circumferential outer wall 219 receives,with an inner circumferential surface thereof, a fluid (e.g., a liquiddroplet, a gas, and a mixture thereof) dispersed outwards from the waferW and guides the received fluid downwards. The mixed fluid of the gasand the liquid droplet reaching a space under the guide plate 218 areseparated, and the liquid droplet is drained through the drain path 216and the gas is exhausted through the exhaust path 217.

The cover member 230 is a ring-shaped member disposed to face theperipheral portion of the top surface of the wafer W held by the waferholding unit 210 when a processing is performed. The cover member 230 isconfigured to rectify a gas flown into the cup body 220 from thevicinity of the peripheral portion of the top surface of the wafer W andconfigured to increase a flow velocity of the gas, so that theprocessing liquid scattered from the wafer W is suppressed fromre-adhering to the top surface of the wafer W again.

The cover member 230 has an inner circumferential surface 231, and theinner circumferential surface 231 is vertically extended and is inclinedoutwards in the radial direction as it approaches the wafer W. Further,the cover member 230 has a horizontal bottom surface 232 facing thewafer W, and a minute gap is vertically provided between the horizontalbottom surface 232 and the top surface of the wafer W. An outerperiphery of the cover member 230 is located outside a peripheral edge(edge) We of the wafer W in the radial direction (see FIG. 3). Further,the peripheral portion of the wafer W as a cleaning target is a regionwithin about 3 mm from the peripheral edge of the wafer W in the radialdirection and covered by the horizontal bottom surface of the covermember 230.

A plan view of FIG. 3 illustrates a state in which the wafer W is heldby the wafer holding unit 210 and the cover member 230 is located at aprocessing position. In FIG. 3, the peripheral edge We of the wafer Whidden from view by being covered with the cover member 230 is indicatedby a dashed dotted line. Further, an inner periphery of the cover member230 is indicated by a reference numeral 5 e.

As depicted in FIG. 2 and FIG. 3, the elevating member 240 configured tomove the cover member 230 up and down is equipped with a plurality of(in the present exemplary embodiment, four) sliders 241 provided to asupporting body 223 configured to support the cover member 230; andguide columns 242 vertically extended through the respective sliders241. Each slider 241 is connected with a cylinder motor (not shown). Bydriving the cylinder motor, each slider 241 is moved up and down alongthe corresponding guide column 242, so that the cover member 230 can bemoved up and down. The cup body 220 is supported by a lifter 243 whichconstitutes a part of a cup elevating device (not shown). If the lifter243 is lowered down from a state shown in FIG. 2, the cup body 220 islowered, and the wafer W can be transferred between the substratetransfer device 17 shown in FIG. 1 and the wafer holding unit 210.

Now, referring to FIG. 2, FIG. 3, FIG. 4A and FIG. 4B, the processingliquid supply units 250A and 250B will be explained. As depicted in FIG.3, the processing liquid supply unit 250A is equipped with a chemicalliquid nozzle 251 configured to discharge a SC-1 solution which is amixture of ammonia, hydrogen peroxide and pure water; and a rinse nozzle252 configured to discharge a rinse liquid (in the present exemplaryembodiment, DIW (pure water)). Further, the processing liquid supplyunit 250A also has a gas nozzle 253 configured to discharge a drying gas(in the present exemplary embodiment, a N₂ gas). The processing liquidsupply unit 2506 is equipped with a chemical liquid nozzle 254configured to discharge a HF solution; a rinse nozzle 255 configured todischarge a rinse liquid; and a gas nozzle 256 configured to discharge adrying gas.

The processing liquid supply unit 250A corresponds to a first processingliquid supply unit of the present disclosure, and the liquids dischargedfrom the chemical liquid nozzle 251 and the rinse nozzle 252 correspondto a first processing liquid of the present disclosure. Further, theprocessing liquid supply unit 2506 corresponds to a second processingliquid supply unit of the present disclosure, and the liquids dischargedfrom the chemical liquid nozzle 254 and the rinse nozzle 255 correspondto a second processing liquid of the present disclosure. Furthermore,the kinds of the first processing liquid and the second processingliquid are not limited to the aforementioned examples, and thepositional relationship of the first processing liquid supply unit andthe second processing liquid supply unit can be reversed.

As shown in FIG. 3 and FIG. 4A, the nozzles 251 to 253 of the processingliquid supply unit 250A are accommodated in a recess 234 formed in theinner circumferential surface of the cover member 230. Each of thenozzles 251 to 253 discharges the processing fluid diagonally downwards,as indicated by an arrow A in FIG. 4B, such that the dischargingdirection indicated by the arrow A has a component of a rotationaldirection Rw of the wafer W. Further, the processing liquid supply unit250A includes a non-illustrated driving device, and each of the nozzles251 and 253 is configured to be position-adjustable by being movedforward and backward in a direction of an arrow B such that the liquidcan be supplied to an optimum position on the wafer W when the liquid isdischarged. The processing liquid supply unit 250B has the sameconfiguration as the processing liquid supply unit 250A.

The control device 4 shown in FIG. 2 controls operations of allfunctional components of the processing unit 16 (e.g., thenon-illustrating rotational driving device, the elevating device 240,the wafer holding unit 210, the various processing fluid supply devices,etc.).

An imaging device 270 corresponds to an imaging unit of the presentdisclosure and is configured to perform a measurement processing uponthe wafer W to be described later. The imaging device 270 is fixed tothe cover member 230 and is disposed such that an opening for performingthe imaging is located vertically above the peripheral portion of thewafer W (in the Z-axis direction).

A configuration of the imaging device 270 according to the exemplaryembodiment will be explained with reference to a cross sectional view ofFIG. 5. The imaging device 270 includes an imaging functional unit 501and an optical guide unit 502. The imaging functional unit 501 isconfigured to image the wafer W through the optical guide unit 502. Theoptical guide unit 502 is configured to guide illumination light to thesurface of the wafer W and guide reflection light (hereinafter, referredto as optical image) to the illumination light on the wafer W to theimaging functional unit 501. The optical guide unit 502 is mounted to aside surface of the cover member 230 with a mounting surface AAtherebetween. Though the cover member 230 has a cross sectional shapeshown in FIG. 2, a circumferential region of the cover member 230corresponding to the mounting surface AA of the optical guide unit 502is notched. However, it should be noted that the entire cross sectionalshape combining the cover member 230 and the optical guide unit 502conforms to the contour of the cross sectional shape of the cover member230 shown in FIG. 2.

The imaging functional unit 501 is equipped with an imaging sensor 503.In the present exemplary embodiment, the imaging sensor 503 isimplemented by a CCD sensor having an effective pixel region of about 2million pixels composed of 1600 pixels and 1200 lines. This imagingsensor 503 only generates a signal corresponding to a luminance signalaccording to a light reception level. An imaging optical mechanism 504having at least a focus adjustment function is provided in front of(ahead of) the imaging sensor 503. The imaging optical mechanism 504includes a lens group and is configured to change positions of lensesfor the focus adjustment. In the present exemplary embodiment, there isprovided an adjusting member 505 with which a user can adjust the focusby adjusting a lens position manually. Since the adjusting member 505 isprovided at a position higher than the cover member 230 and the imagingfunctional unit 501, the user of the apparatus can easily operate itmanually.

A mirror 506 is provided in front of the imaging optical mechanism 504in an optical axis direction. Since the imaging device 270 is providedwith the opening which is opened toward the vertically upward directionof the wafer W (in the Z-axis direction), the optical image of thesurface of the wafer W as the imaging target is oriented in a verticallyupward direction LZ. The mirror 506 converts the direction of theoptical image to a horizontal direction LX and allows the direction ofthe optical image to be coincident with the optical axis of the imagingsensor 503 and the imaging optical mechanism 504.

An illumination room 507 is for generating therein irradiation light tothe wafer W and includes therein a LED illumination unit 508 and amirror 509. The LED illumination unit 508 is configured to generate theirradiation light for irradiating the wafer W. The mirror 509 reflectsthe irradiation light from the LED illumination unit 508 verticallydownwards and transmits the optical image in the LZ direction. Theopening 510 has a rectangular cross sectional shape and is configured toguide the irradiation light reflected from the mirror 509 of theillumination room 507 downwards. The cross section of the opening 510may have a circular shape, alternatively.

A glass window 511 has the same cross sectional shape as the opening 510at an upper end thereof and serves to guide the irradiation lightincident from the opening 510 to the surface of the wafer W as theimaging target. Further, the glass window 511 also guides the reflectionlight form the surface of the wafer W in the LZ direction as the opticalimage. A bottom surface 512 of the glass window 511 is a lower end ofthe imaging device 270 and has a flat surface facing the peripheralportion of the top surface of the wafer W, and this flat surface is setto be the same height as the bottom surface 232 of the cover member 230of FIG. 2. Further, in order to conform to the shape of the cover member230, an outer side surface 513 of the glass window 511 is recessed at aheight of an outer bottom surface of the cover member 230 as compared toan upper portion thereof. Accordingly, in an overall view, the glasswindow 511 is formed to have an L-shaped cross section.

While the processing liquid supply unit 250A (250B) is supplying thechemical liquid or the rinse liquid to the wafer W, an atmospherecontaining the chemical liquid or moisture passes through a region belowthe opening 510 of the imaging device 270. The glass window 511 has afunction of blocking this atmosphere from entering the opening 510 inorder to suppress this atmosphere from entering the inside of thehousing of the imaging device 270 and rusting the internal structure.Since the glass window 511 is a transparent member, it blocks theatmosphere but transmits the irradiation light or the reflection lightfrom the surface of the wafer W.

An inner cover member 514 is provided to suppress the glass window 511from being covered with the liquid, and has the same shape as the innercircumferential surface 231 of the cover member 230 shown in FIG. 2. Asstated, by forming the same contour as the cross section of the covermember 230 with the bottom surface 512 and the outer side surface 513 ofthe glass window 511 and the inner cover member 514, an air flow whichflows into the cup body 220 from the cover member 230 can be suppressedfrom being disturbed due to the shape of the imaging device 270.

An imaging controller 515 of the imaging functional unit 501 controls animaging operation of the imaging device 270 and performs an imageprocessing upon the image. The optical image received by the imagingsensor 503 is photoelectrically converted and then converted to ananalog signal corresponding to the luminance signal. Then, this analogsignal is sent to the imaging controller 515. The imaging controller 515generates a digital signal indicating the luminance by performing A/Dconversion of the received analog signal, and forms a 1-frame image byperforming a preset image processing. Further, the imaging controller515 may generate a moving image by acquiring still image framescontinually. Through a cable 516, a control signal can be transmittedto/from an external device, and transmits the image to the externaldevice.

A measurement processing system 600 according to the exemplaryembodiment will be discussed with reference to FIG. 6. The presentsystem includes the imaging device 270, a measurement processing device601, an information processing device 602 and the control device 4.

The imaging device 270 includes, as described above with reference toFIG. 5, the imaging sensor 503, the imaging optical mechanism 504, theLED illumination unit 508, the imaging controller 515, the cable 516,and so forth. As will be described later, the imaging controller 515 mayperform the imaging under modified imaging conditions based on thecontrol signal transmitted from the measurement processing device 601through the cable 516.

The measurement processing device 601 is configured to measure a cutwidth and an eccentric amount to be described later by processing theimage obtained by the imaging device 270. The measurement processingdevice 601 may have at least a controller 603 and a storage unit 604within a housing thereof.

The controller 603 controls blocks of the measurement processing device601, and also controls the operation of the imaging device 270. Further,by executing a measurement processing program to be described later, thecontroller 603 performs calculation regarding the cut width or theeccentric amount. The storage unit 604 stores therein the measurementprocessing program performed by the controller 603 and an imageprocessing recipe to be described later. Furthermore, the storage unit604 temporarily stores the image received from the imaging device 270through the cable 516, and also stores the measurement result calculatedby the controller 603. The measurement processing device 601 is capableof sending/receiving various kinds of information to/from theinformation processing device 602 and the control device 4 through acommunication line 605.

The information processing device 602 is configured to accumulate theimage and the measurement result sent from the measurement processingdevice 601 and transmits these information to the control device 4. Theinformation processing device 602 includes at least a controller 606 anda storage unit 607 within a housing thereof. The controller 606 controlsblocks of the information processing device 602 and is capable ofsending various kinds of instructions to the measurement processingdevice 601. Furthermore, the controller 606 also has a function ofanalyzing the measurement result. The storage unit 607 accumulatestherein the image and the measurement result sent from the measurementprocessing device 601. The information processing device 602 is capableof sending/receiving various kinds of information to/from themeasurement processing device 601 and the control device 4 through thecommunication line 605.

The control device 4 controls an overall operation of the substrateprocessing system 1, as shown in FIG. 1, and can be operated incooperation with the measurement processing device 601 and theinformation processing device 602. The control device 4 is capable ofsending/receiving various kinds of information to/from the measurementprocessing device 601 and the information processing device 602 throughthe communication line 605. Furthermore, the control device 4 isconnected to a manipulation device 608 and a display device 609. Thedisplay device 609 is configured to display the image and the processedimage received from the information processing device 602. Themanipulation device 608 includes an input device such as, but notlimited to, a keyboard, a mouse, or a touch panel, and is capable ofselecting a wafer processing recipe in which a processing to beperformed on the wafer W as a measurement target is described.

In the present exemplary embodiment, the individual devices constitutingthe measurement processing system 600 are accommodated in a housing ofthe substrate processing system 1. However, the exemplary embodiment isnot limited thereto, and a single device or a plurality of devices maybe accommodated in a separate housing, and the communication line 605may be implemented by a wired or wireless network. As an example, theinformation processing device 602 may be accommodated in another housingto be separate from the substrate processing system 1, and the substrateprocessing system 1 may be remote-controlled.

Now, an overall flow of a substrate processing and a measurementprocessing performed by the substrate processing system 1 and themeasurement processing system 600 according to the exemplary embodimentwill be discussed with reference to FIG. 7. This processing operation isperformed for every single set of 25 sheets of wafers W, and theflowchart of FIG. 7 describes the processing operation for a singlesheet of wafer W within a single set.

First, the wafer W is carried into the processing unit 16 (S101). Here,the cover member 230 is placed at a retreat position (a position abovethat shown in FIG. 2) by the elevating device 240, and the cup body 220is lowered by the lifter 243 of the cup elevating device. Then, theshutter 263 of the housing 260 is opened, and a transfer arm of thesubstrate transfer device 17 shown in FIG. 1 is advanced into thehousing 260, and the wafer W held by the transfer arm of the substratetransfer device 17 is placed directly above the wafer holding unit 210.Thereafter, the transfer arm is lowered to a position lower than the topsurface of the wafer holding unit 210, and the wafer W is positioned onthe top surface of the wafer holding unit 210. Then, the wafer W isattracted to and held by the wafer holding unit 210. Afterwards, theempty substrate transfer device 17 is retreated out of the housing 260.Subsequently, the cup body 220 is moved up and returned back to theposition shown in FIG. 2, and the cover member 230 is lowered to theprocessing position shown in FIG. 2. Through this sequence, the carry-inof the wafer W is completed, and a state shown in FIG. 2 is obtained.

Then, a wafer processing is performed with the chemical liquid or thelike (S102). Details of the wafer processing according to the presentexemplary embodiment will be elaborated later.

Subsequently, a measurement processing upon the wafer W is performed(S103). Details of the measurement processing according to the presentexemplary embodiment will be elaborated later.

Finally, a carry-out of the wafer W from the processing unit 16 isperformed (S104). Here, the cover member 230 is raised to the retreatposition, and the cup body 220 is lowered. Then, the shutter 263 of thehousing 260 is opened, and the empty transfer arm of the substratetransfer device 17 is advanced into the housing 260. The empty transferarm is positioned under the wafer W held by the wafer holding unit 210and is then raised. Accordingly, the transfer arm receives the wafer Wfrom the wafer holding unit 210 which stops the attraction of the waferW. Thereafter, the transfer arm holding the wafer W is retreated fromthe housing 260. Through these operations, the series of liquidprocessings upon the single sheet of wafer W is ended.

Now, the wafer processing performed in the process S102 according to thepresent exemplary embodiment will be elaborated with reference to aflowchart of FIG. 8.

First, a first chemical liquid processing is performed (S201). Here,while rotating the wafer W and discharging the N₂ gas from the gasdischarge openings 213 and 214 of the cup body 220, the wafer W,particularly, the peripheral portion of the wafer W as a processingtarget region is heated up to a temperature (e.g., about 60° C.)suitable for the chemical liquid processing. If the wafer W is heatedsufficiently, the chemical liquid SC-1 is supplied to the peripheralportion of the top surface (device forming surface) of the wafer W fromthe chemical liquid nozzle 251 of the processing liquid supply unit 250Awhile the wafer W is being rotated, so that an unnecessary film on theperipheral portion of the top surface of the wafer W is removed.

Then, a first rinsing processing is performed (S202). Here, after thechemical liquid processing is performed for a preset time period, thedischarge of the chemical liquid from the chemical liquid nozzle 251 isstopped, and a rinsing processing is performed by supplying a rinseliquid (DIW) to the peripheral portion of the wafer W from the rinsenozzle 252 of the processing liquid supply unit 250A. Through thisrinsing processing, the chemical liquid and a reaction product remainingon the top surface and the bottom surface of the wafer W are washedaway. Here, a drying processing which is the same as a process S205 tobe described later may also be performed.

Thereafter, a second chemical liquid processing is performed (S203).Here, a chemical liquid processing is performed on the wafer W to removean unnecessary material that cannot be removed in the first chemicalliquid processing. As in the first chemical liquid processing, whilerotating and heating the wafer W, the chemical liquid HF is supplied tothe peripheral portion of the top surface (device forming surface) ofthe wafer W from the chemical liquid nozzle 254 of the processing liquidsupply unit 2506, so that an unnecessary film on the peripheral portionof the top surface of the wafer W is removed.

Then, a second rinsing processing is performed (S204). Here, after thechemical liquid processing is performed for a preset time period, thedischarge of the chemical liquid from the chemical liquid nozzle 254 isstopped while continuously rotating the wafer W and discharging the N₂gas from the gas discharge openings 213 and 214. Then, the rinse liquid(DIW) is supplied to the peripheral portion of the wafer W from therinse nozzle 255 of the processing liquid supply unit 2506, so that therinsing processing is performed. Through this rinsing processing, thechemical liquid and a reaction product remaining on the top and bottomsurfaces of the wafer W can be washed away.

Finally, a drying processing is performed (S205). After the rinsingprocessing is performed for a predetermined time period, the dischargeof the rinse liquid from the rinse nozzle 255 is stopped whilecontinuously rotating the wafer W and discharging the N₂ gas from thegas discharge openings 213 and 214. Then, the drying gas (N₂ gas) issupplied to the peripheral portion of the wafer W from the gas nozzle256, so that the drying processing is performed.

Now, referring to FIG. 9A and FIG. 9B, a relationship between a liquidstate on the wafer W and a placement of the imaging device 270 in thechemical liquid processing of the process S102 will be explained.

First, the first chemical liquid processing of discharging a firstchemical liquid (SC-1 solution) toward the wafer W in the process S201will be discussed.

As depicted in FIG. 9A, the wafer W is rotated in a first rotationaldirection R₁. A rotation number is set to be, for example, 2000 rpm to3000 rpm, and the first chemical liquid is supplied onto the peripheralportion of the top surface of the wafer W from the chemical liquidnozzle 251. In FIG. 9A, the first chemical liquid existing (loaded) onthe top surface of the wafer W is indicated by a reference numeral 901.As illustrated, the first chemical liquid supplied onto an arrivalregion 902 of the peripheral portion of the wafer W being rotated in thefirst rotational direction R₁ is moved to an outer side of the wafer Wby a centrifugal force due to the rotation, and is scattered outwardsfrom the wafer W. The first chemical liquid scattered outwards from thewafer W is drained to the outside through the drain path 216 via theinner circumferential surface of the circumferential outer wall 219 ofthe cup body 220.

A position 903 on the wafer W at which the first chemical liquid iscompletely scattered off the wafer W depends on parameters such as avelocity of the first chemical liquid discharged from the chemicalliquid nozzle 251, a rotational speed of the wafer W and a distance fromthe aforementioned first chemical liquid arrival region 902 to a sideend portion of the wafer W. For example, if the rotation number isreduced, the chemical liquid becomes difficult to scatter by thecentrifugal force, so that a region where the chemical liquid exists isincreased, as indicated by a dotted line.

The same goes for the rinse nozzle 252 and the rinse liquid reaching thewafer W after being discharged in the process S202. Though an arrivalregion of the rinse liquid from the rinse nozzle 252 is substantiallythe same as the arrival region 902 of the first chemical liquid, it isslightly moved to the front position in the rotational direction and tothe center side of the wafer W, as compared to the arrival region of thefirst chemical liquid. Therefore, the region where the first chemicalliquid has flown on the top surface of the wafer W can be securelycleaned by the rinse liquid.

Now, a second chemical liquid processing of discharging the secondchemical liquid HF toward the wafer W in the process S203 will beexplained.

As depicted in FIG. 9B, the wafer W is rotated in a second rotationaldirection R₂ which is opposite to the first rotational direction R₁. Arotation number is set to be, for example, 2000 rpm to 3000 rpm, and thesecond chemical liquid is supplied onto the peripheral portion of thetop surface of the wafer W from the chemical liquid nozzle 254. Asillustrated, the second chemical liquid existing (loaded) on the topsurface of the wafer W is indicated by a reference numeral 904. Thesecond chemical liquid supplied onto an arrival region 905 shows thesame behavior as the first chemical liquid in the process S201. Then, inthe process S204, the rinse nozzle 255 and the rinse liquid reaching thewafer W after being discharged are the same as described in the case ofthe rinse nozzle 252.

As stated above, by rotating the wafer W in the reverse directions inthe processes S201 and S202 and in the processes S203 and S204, theregions of the first chemical liquid 901 and the second chemical liquid904 on the top surface of the wafer W and the positions 903 and 906where the chemical liquids are completely scattered off the wafer W canbe adjusted. Here, an angle formed by connecting the processing liquidsupply unit 250A and the processing liquid supply unit 250B with thecenter of the wafer W is defined as “θ_(X)” degree; an angle formed byconnecting the arrival region 902 and the region 903 with the center ofthe wafer W, “θ_(A)” degree; and an angle formed by connecting thearrival region 905 and the region 906 with the center of the wafer W,“θ_(B)” degree (see FIG. 9B). At this time, these angles need to satisfya relational expression of θ_(X)+θ_(A)+θ_(B)<360°. For example, whenθ_(X)=60°, by setting θ_(A)<120° and θ_(B)<120°, this condition can besatisfied, and the positions 903 and 906 where the chemical liquids arecompletely scattered off do not intersect on the circumference.Accordingly, it is possible to suppress generation of salt that might becaused as the processing liquids scattered from the wafer W are mixedand react with each other within the cup body 220.

Further, with respect to the first rotational direction R₁, the opening510 is located in front of the arrival region 902 of the first chemicalliquid and the rinse liquid on the wafer W, and with respect to thesecond rotational direction R₂, the opening 510 is located in front ofthe arrival region 905 of the second chemical liquid and the rinseliquid on the wafer W. By locating the opening 510 of the imaging device270 in this way, it is possible to suppress the opening 510 from beingcovered with the liquid when the chemical liquid processing is beingperformed.

FIG. 10 is a diagram illustrating an angle of view of the imaging device270 with respect to the wafer W. As depicted in FIG. 10, the imagingdevice 270 sets a rectangular region located at the periphery of thewafer W as the angle of view 1001.

The measurement processing device 601 uses images cut from the entireimage of the angle of view 1001 to measure the cut width and theeccentric amount. To elaborate, in the angle of view 1001 of the imagingdevice 270, cut images of five regions 1001 a, 1001 b, 1001 c, 1001 dand 1001 e whose positions are adjusted along the edge of the wafer Ware used. Each cut image has a size of, for example, 320 pixels in theX-axis direction×240 pixels in the Y-axis direction. Further, in thepresent exemplary embodiment, two images are acquired for each angle ofview 1001 under a first imaging condition and a second imagingcondition, respectively, as will be described later.

Referring to FIG. 11, an arrangement relationship of the imaging device270, the processing unit 16 and the wafer W will be explained. As shownin the figure, the wafer W has a round at the peripheral portionthereof. A processing film is formed on the top surface of the wafer Wand only the processing film on the peripheral portion thereof isremoved (cut). Further, the wafer W has a diameter of 300 mm and has noerror in the circumferential direction thereof.

In case that the imaging device 270 is appropriately provided, an innerend (upper end) of the angle of view of the imaging device 270 in thelongitudinal (X-axis) direction is located above the processing film ofthe wafer W, and an outer end (lower end) thereof is located above thetop surface 212 of the inner circumferential portion 211 shown in FIG.2. Thus, on the image obtained by the imaging device 270, a processingfilm region 1101, a cut surface region 1102, a round region 1103 and atop surface region 1104 is arranged in sequence from the inner end(upper end) of the angle of view. Here, the processing film region 1101is a region where the formed processing film remains without beingremoved by the chemical liquid. In a region where the formed processingfilm is removed, the cut surface region 1102 is a flat surface regionnot including the round which is formed at the circumferential edge ofthe wafer W. The round region 1103 is a rounded area from which theprocessing film is removed or at which no processing film is originallyformed. The top surface region 1104 is a region formed ahead of thecircumferential edge of the wafer W.

Further, the cut width refers to a width of a region, where noprocessing film exits (a region from which the processing film isremoved or at which no processing film is originally formed), which iscomposed of the cut surface region 1102 and the round region 1103between the circumferential edge of the processing film and thecircumferential edge of the wafer W at the circumferential edge of thewafer W. Further, a width of the cut surface region 1102 is referred toas a cut surface width, and a width of the round region 1103 is referredto as a round width.

Now, an operation of measuring the cut width and the eccentric amount inthe process S103 performed by the cooperation of the individual devicesof the present exemplary embodiment will be explained with reference toflowcharts of FIG. 12A and FIG. 12B. The measuring operation shown inthis flowchart is implemented as the controller 603 of the measurementprocessing device 601 executes the measurement processing program storedin the storage unit 604.

When the overall flow transits to the process S103, the arrangementrelationship of the imaging device 270, the processing unit 16 and thewafer W is already in the state shown in FIG. 11.

First, the measurement processing device 601 sets the first imagingcondition and the second imaging condition to be described below as animaging condition under which the imaging device 270 performs theimaging operation (process S301). At this time, the wafer W is locatedat a preset initial rotation position.

Then, the imaging of the wafer W is performed under the first imagingcondition (process S302). Here, the controller 603 of the measurementprocessing device 601 sends a control instruction to the imaging device270 to allow the imaging operation to be performed under the firstimaging condition. In response to the control instruction, the imagingcontroller 515 controls the imaging sensor 503 and the LED illuminationunit 508 to perform the imaging operation under the first imagingcondition according to the received control instruction. The imagingcontroller 515 converts a signal obtained by the imaging of the imagingsensor 503 into an image of a luminance signal of a single frame, andsends this image to the measurement processing device 601. The imagesent to the measurement processing device 601 is stored in the storageunit 604. Here, details of the first imaging condition and the actualimage state will be described later.

After the imaging operation under the first imaging condition, theimaging of the wafer W is performed under the second imaging condition(process S303). This operation is the same as the process S302. Detailsof the second imaging condition and the actual image state will beexplained later.

Subsequently, it is determined whether the imaging is conducted at allof preset positions (S304). In the present exemplary embodiment, sincethe imaging is performed 360 times while rotating the wafer W by 1degree from the position where the imaging is performed in the processesS302 and S303, the determination of “Yes” is only made after the imagingis performed at 360 positions.

Here, since the imaging is performed only at the initially set positionin the process S301 (process S304: No), the processing proceeds to arotating operation of a process S305.

The control device 4 drives a rotational driving unit to rotate thewafer W by 1 degree by rotating the wafer holding unit 210. As a result,a next imaging position is allowed to be located directly under theimaging device 270 (S305).

If the rotating operation is finished, the processing returns back tothe process S302, and the same imaging operation and rotating operationas stated above are performed. If these operations are performed 360times, it is determined that the imaging is conducted at all positions(process S304: Yes), and the processing proceeds to a process S306 wherean image analysis processing is conducted by using 360 sets of first andsecond images (S306). Then, as a measurement result, the cut width andthe eccentric amount are obtained (S307). Details of the image analysisprocessing will be described later.

In the present exemplary embodiment, the controller 603 sends, to theinformation processing device 602, the first image obtained under thefirst imaging condition, the second image obtained under the secondimaging condition, and the cut width (S308). The information processingdevice 602 stores the received first and second images in the storageunit 607.

Subsequently, details of the imaging operation and the image analysisprocessing in the processes S302 to S306 will be elaborated.

Information measured in the present exemplary embodiment is the cutwidth of the wafer W. With reference to the relationship shown in FIG.11, this value can be calculated by the following expressions (1) to(3).

Cut width (mm)=width (mm) of cut surface region 1102+width (mm) of roundregion 1103  Expression (1)

Here,

Width (mm) of cut surface region 1102=(position (pixel) of cut surfaceboundary 1110−position (pixel) of processing film boundary 1109)/scalingvalue (pixel/mm)  Expression (2)

Width (mm) of round region 1103=(position (pixel) of wafercircumferential edge 1111−position (pixel) of cut surface boundary1110)/scaling value (pixel/mm)  Expression (3)

In the above expressions (1) to (3), the term “position (pixel)” refersto a count value of pixels from the inner end of the cut image in thetransversal direction. In the present exemplary embodiment, since thenumber of pixels in the transversal direction (X-axis direction) of thecut image is 320, the “position (pixel)” may have a value ranging from 1to 320.

Here, it is assumed that a corresponding relation between the number ofpixels of the image obtained by the camera and a length (mm) of a planeon which the wafer W is placed is previously measured and determined byusing a scaling wafer or the like. In the present exemplary embodiment,the value of “scaling value”=20 pixels/mm is stored in the storage unit604.

In the present exemplary embodiment, as depicted in FIG. 10, fiveregions are extracted from the single image, and the cut width of eachof these regions is calculated. Then, an average value of these cutwidths is set as a final cut width in each region.

As can be seen from the expressions (1) to (3), in order to calculatethe cut width, the three boundary positions of (a) the position of thecut surface boundary 1110, (b) the position of the processing filmboundary 1109 and (c) the position of the wafer circumferential edge1111 need to be specified from a variation amount (luminance edgeamount) in a luminance level of pixels of the image. Here, the luminanceedge amount can be obtained by using a method of calculating a peakvalue from an absolute value of a difference in the luminance valuesbetween adjacent pixels or a method of applying a commonly known edgefilter to the image.

The respective regions 1101 to 1104 of the wafer W and the processingunit 16 of the present exemplary embodiment have their own reflectioncharacteristics caused by the materials or structures thereof. In casethat irradiation light having the same illumination level which isgenerated from the LED illumination unit 508 is incident, the cutsurface region 1102 may exhibit a higher reflection light level (brightgray) than a reflection light level (gray) of the processing film region1101 due to a difference in their materials, for example. Meanwhile,though the cut surface region 1102 and the round region 1103 are made ofthe same material, since the round region 1103 is inclined, a reflectionlight level of the round region 1103 in the direction of the imagingsensor 503 is low (close to black).

As for the top surface region 1104, though attenuation of light occursbecause a reflection surface thereof is relatively far, the top surfaceregion 1104 still exhibits a certain reflection light level (gray closeto black).

Resultantly, the illumination level of the optical image received by theimaging sensor 503 is higher in the order of the cut surface region1102, the processing film region 1101, the top surface region 1104 andthe round region 1103.

As stated above, according to the exemplary embodiment, in case of usingthe illumination light having the same illumination level from the LEDillumination unit 508, the range of the illumination level in theoptical image is very large. Thus, with the imaging sensor 503 having adynamic range of a typical width, it may not be possible to perform theimaging such that the illumination levels of all the regions haveappropriate luminance levels. Since the accurate luminance edge cannotbe calculated from the image which does not have an appropriateluminance level, there may be caused an error in specifying the threeboundary positions (a) to (c).

According to the present exemplary embodiment, the first imagingcondition and the second imaging condition which are different inbrightness conditions are previously prepared. Then, by performing theimaging two times under these first and second imaging conditions, theaforementioned problem can be solved. For the convenience ofexplanation, the second imaging condition and a second image will befirst explained.

For the second imaging condition, a condition in which an emphasis isput on an intermediate illumination level is set to acquire a relativelybright image and accurately specify (b) the position of the processingfilm boundary 1109. That is, it is set such that the illumination levelof the processing film region 1101 and the illumination level of the cutsurface region 1102 in the optical image has a wide width of gradationwhen the illumination level of the optical image is converted to theluminance signal. Specifically, this can be adjusted by setting asensitivity of CCD (e.g., ISO sensitivity) or a light receiving time ofCCD with a non-illustrated exposure adjusting device, for example.

Here, since the second imaging condition puts the emphasis on theintermediate illumination level, reproducibility of a region of a lowillumination level is low. That is, since the gradation of theillumination levels of the top surface region 1104 and the round region1103 is narrowed, each region is turned out to be an image having acolor close to black.

A schematic view of the second image obtained under the second imagingcondition is illustrated in FIG. 13. Since the gradation of theluminance signal levels of the processing film region 1101 and the cutsurface region 1102 is sufficiently maintained, the variation in theluminance levels of the pixels of these two regions, that is, theluminance edge can be easily detected, and (b) the position of theprocessing film boundary 1109 can be accurately specified. Furthermore,(a) the position of the cut surface boundary 1110 can also be specifiedaccurately. Meanwhile, the top surface region 1104 and the round region1103 are all located at low luminance signal values (nearly black). Forthis reason, the detection of the luminance edge is difficult, and (c)the position of the wafer circumferential edge 1111 cannot be specified.

In the present exemplary embodiment, (c) the position of the wafercircumferential edge 1111 is specified from a first image which isrelatively dark and is obtained under the first imaging condition, i.e.,the other imaging condition.

The first imaging condition is set as a condition in which an emphasisis put on a low illumination level. That is, it is set such that theillumination level of the round region 1103 has a wide width ofgradation when the illumination level of the optical image is convertedto the luminance signal. To elaborate, this may be adjusted by setting asensitivity of CCD (e.g., ISO sensitivity) to be higher than that of thesecond imaging condition or by setting the light receiving time of CCDto be longer than that of the second imaging condition.

Here, since the first imaging condition puts the emphasis on the lowillumination level, reproducibility of a region of the intermediateillumination level is low. That is, since the gradation of theillumination levels of the processing film region 1101 and the cutsurface region 1102 is narrowed, each region is turned out to be animage having a color close to white.

A schematic view of the first image obtained under the first imagingcondition is illustrated in FIG. 14. Since the gradation of theluminance signal values of the top surface region 1104 and the roundregion 1103 are sufficiently maintained, the luminance edge can beeasily detected, so that (c) the position of the wafer circumferentialedge 1111 can be accurately specified. Meanwhile, the processing filmregion 1101 and the cut surface region 1102 are all located at highluminance signal values (nearly white). For this reason, the detectionof the luminance edge is difficult, and (b) the position of theprocessing film boundary 1109 cannot be specified.

As stated above, by using the first image based on the first imagingcondition and the second image based on the second imaging condition,(a) the position of the cut surface boundary 1110, (b) the position ofthe processing film boundary 1109 and (c) the position of the wafercircumferential edge 1111 can be accurately obtained.

The controller 603 calculates the cut width by applying theaforementioned position information (a) to (c) to the expressions (1) to(3). The cut width is calculated for each of the other cut images 1000a, 1000 b, 1000 d and 1000 e, and an average value of these cut widthsis determined as a final cut width obtained for the angle of view 1001.

Now, an eccentric state of the wafer W with respect to the holding unit210 will be explained with reference to FIG. 15. A center position WO ofthe wafer W and a center position HO of the wafer holding unit 210 maybe deviated in the X-axis and Y-axis directions when the substratetransfer device 17 places the wafer W on the wafer holding unit 210. Forexample, this phenomenon may occur due to insufficient adjustment of thesubstrate transfer device 17, abrasion of a constituent member resultedfrom a long time of usage thereof, and so forth. In the presentexemplary embodiment, a deviation amount from the center position HO isdefined as an “eccentric amount WD.”

FIG. 15 illustrates a positional relationship between the cut regions1000 a to 1000 e of the image and the wafer W. Immediately after thesubstrate transfer device 17 places the wafer W on the wafer holdingunit 210 at a deviated position, the center position WO of the wafer Wis located at somewhere on a circular ring 1501. In case that the waferW is rotated as indicated by an arrow, the center position WO of thewafer W surely passes through positions WO1 and WO2 on the X-axis ofFIG. 15.

As in the present exemplary embodiment, when the imaging device 270 isfixed and the imaging is performed while rotating the wafer W which iseccentric, there occurs a phenomenon that the position of theaforementioned wafer circumferential edge 1111 changes periodically.When viewed from the cut regions 1000 a to 1000 e of the image, thewafer circumferential edge 1111 is located at a position 1502 to have aminimum value when the center of the wafer W is located at the positionWO1, and is located at a position 1503 to have a maximum value when thecenter of the wafer W is located at the position W02.

A difference between the center positions WO1 and WO2 is equal to adifference between the maximum value and the minimum value of the wafercircumferential edge 1111. Accordingly, the eccentric amount WD can beobtained by an expression (4) of WD=(maximum value of the wafercircumferential edge 1111−minimum value of the wafer circumferentialedge 1111)/2.

FIG. 16 is a graph showing a measurement result of the cut width withrespect to a rotation angle of the wafer W when the wafer W is rotated360 degrees in the measurement processing shown in FIG. 12A and FIG.12B.

This example shows a measurement result when the wafer processing of theprocess S102 of FIG. 7 is performed while the wafer W is eccentricallyplaced. Like the wafer circumferential edge 1111, the cut width alsochanges periodically depending on the angle. In the present exemplaryembodiment, the measurement processing device 601 specifies an averagevalue “Ave,” a maximum value “Max,” and a minimum value “Min” of the cutwidth from the measurement results at 360 points. Here, if the variationof the processing film boundary 1109 with respect to the periodicvariation of the wafer circumferential edge 1111 in the images at the360 points can be considered to be negligibly small, the variationamount of the wafer circumferential edge 1111 becomes dominant in thevariation amount of the cut width. Thus, the eccentric amount WD can becalculated by an expression (5) of WD=(maximum value “Max”−minimum value“Min”)/2.

The measurement processing device 601 sends, to the informationprocessing device 602, the average value “Ave,” the maximum value “Max,”and the minimum value “Min,” at 360 points which are informationindicating the cut width and the eccentric amount.

The information processing device 602 generates information to bedisplayed on the display device 609 connected to the control device 4based on the measurement result information received from themeasurement processing device 601.

FIG. 17 is a diagram illustrating an example of a display screen 1700configured to display the measurement result information to be displayedon the display device 609. A recipe information window 1701 displays setvalues of a chemical liquid processing to be performed on the wafer Wwhich is a measurement processing target. For example, the recipeinformation window 1701 may display a set value of the cut width. Therecipe information window 1701 also displays the film kind on the waferW to be processed.

A measurement result window 1702 displays the cut width obtained as themeasurement result, here, the average value “Ave.” Further, themeasurement result window 1702 also displays the eccentric amount WDcalculated by the expression (5).

A first image window 1703 and a second image window 1704 are configuredto display the images obtained under the first imaging condition and thesecond imaging condition, respectively, for checking.

A graph window 1705 is configured to visualize the various measurementresults such as the variation of the cut width depending on the angleshown in FIG. 16, for example, and investigate the characteristicthereof.

The cut width obtained in the present exemplary embodiment is used asinformation for adjusting the processing liquid supply unit 250 of theprocessing unit 16, for example. A user of the system may fine-adjustthe position of the chemical liquid nozzle 208, for example, based on adifference value between the previously set cut width and the actuallymeasured cut width. Further, as will be described later in a secondexemplary embodiment, if the eccentric amount is obtained, a holdingposition adjustment for the wafer W can be performed.

As stated above, according to the present exemplary embodiment, theopening 510 of the imaging device 270 is located in front of (ahead of)the arrival region 902 of the processing liquid on the wafer W in thefirst rotational direction R₁. With this configuration, even if theimaging device 270 is provided at the cover member 230 to image theperipheral portion of the wafer W while holding the wafer W, the imagingdevice 270 can be suppressed from being covered with the liquid, so thatthe imaging can be performed successfully. Further, the imaging device270 is provided by notching a part of the cover member 230 and isdisposed to have the same cross section as that of the cover member 230at other positions. In this way, by allowing the imaging device 270 tohave the same shapes of the inner side surface and the bottom surface asthose of the cover member 230, the disturbance of the air flow or thelike can be avoided in the vicinity of the imaging device 270, so thatthe liquid processing can be performed successfully.

First Modification Example of First Exemplary Embodiment

As a first modification example of the above-described first exemplaryembodiment, two cases of system configuration regarding a focusadjustment will be explained.

First, a focus adjustment by manipulating the adjusting member 505 ofthe imaging device 270 shown in FIG. 5 will be explained. The focusadjustment by the user can be rapidly performed while checking whetherthe wafer W is well focused by seeing the image in real time. In thepresent exemplary embodiment, the image is displayed on the displaydevice 609.

To elaborate, while the focus adjustment operation is being performed,the imaging controller 515 acquires the images of the wafer Wconsecutively at a frame rate of, e.g., 5 fps by operating the imagingsensor 503, and then, sends the acquired images to the measurementprocessing device 601. The measurement processing device 601 processesthe received consecutive images such that they can be displayed on thedisplay device 609, and then, sends the processed images to the controldevice 4. The control device 4 allows the received images to bedisplayed on the first image window 1703 or the second image window 1704shown in FIG. 17, for example. In this case, the display device 609 neednot be configured as one body with the housing of the substrateprocessing system 1 but may be configured as a portable terminal deviceconnected to the substrate processing system 1 via wire or wirelessly toimprove convenience.

The above is the manual focus adjustment operation. This focusadjustment is performed by using a sample wafer prior to measuring anactual cut width, and cannot be performed while performing the actualmeasurement processing upon the wafer W as a processing target.

As a second case, a configuration in which the imaging device 270 has anauto-focusing function to perform the focus adjustment automatically,not manually, will be discussed.

In this present modification example, the imaging optical mechanism 504shown in FIG. 5 incorporates therein a non-illustrated actuator formoving the lens group automatically. The imaging controller 515 has aconfiguration in which the autofocus (AF) control through a contrastmethod can be performed. Further, the imaging controller 515 sends, tothe actuator, a control signal determined based on the image obtained bythe imaging sensor 503.

To elaborate, the imaging controller 515 sets an operation mode suchthat the imaging sensor 503 can record a moving image at a rate of,e.g., 5 fps. The imaging controller 515 acquires an AF evaluation valueindicating a degree of image blur from the five cut regions shown inFIG. 10. Then, based on the AF evaluation value, the imaging controller515 moves the lens group of the imaging optical mechanism 504 in adirection in which the image blur is decreased. While repeating thecontrol on the consecutive frames, if it can be determined that theimage blur is minimized based on the AF evaluation value, it isdetermined that focusing is achieved.

Referring to FIG. 12B, a measurement processing according to the presentexemplary embodiment will be described. The same processing as that ofthe flowchart of FIG. 12A will be assigned the same numeral, andredundant description will be omitted.

In the present exemplary embodiment, after the focusing is achieved byperforming the AF operation at each of the 360 points of the wafer W,the imaging is conducted.

In a process S311, as described above, the AF control by the contrastmethod is performed. Then, in a process S312, information at the focusedposition, i.e., (a) driving information of the actuator or (b) lensposition information, (C) a time that has elapsed from the beginning ofthe AF control until the focusing is achieved, and so forth are stored.Thereafter, the imaging operation already described in the process S302is performed.

By performing the above-describe control, it is possible to acquire theimage of which focus is well-adjusted at each of all imaging positions,so that the measurement processing can be performed highly accurately.Furthermore, by analyzing the AF information (a), (b) and (c) obtainedin the process S312, the characteristic of the wafer W can also beinvestigated. By way of example, in case that the AF information variesperiodically depending on the angle, as in the example of the cut widthshown in FIG. 16, there is a likelihood that a distance between thewafer W and the imaging device 270 changes periodically. If the distancevaries periodically, it implies that the wafer W is highly likely to bebent (deformed). In such a case, user's attention may be called throughthe display device 609.

Second Modification Example of First Exemplary Embodiment

As a second modification example of the above-described first exemplaryembodiment, there will be described an example where the measurementprocessing or the wafer processing is additionally performed in thewhole process flow of FIG. 7. Assume that, as the measurement result inthe process S103 of FIG. 7, the cut width does not form a smooth curvedline as in FIG. 16 but includes a multiple number of smallirregularities which appear several times (not shown). Since thisphenomenon occurs especially when the processing film boundary 1109 isnot regular in the diametrical direction, this means that the processingfilm is not removed in a uniform width in the circumferential directionand there exist partial film residues. The partial film residues may becaused due to an insufficient processing time of the chemical liquidprocessing, not due to insufficient accuracy in setting the nozzleposition. Thus, if the small irregularity is found in the measurementresult of the cut width, there is performed a control of repeating thesame chemical liquid processing one more time. As a result, since asufficient amount of chemical liquid is supplied to the remaining filmagain, the film residues can be easily removed. Thus, a fine processingresult of the wafer W as the measurement target can also be obtained.

To elaborate, after the measurement processing of the process S103 inthe overall flow of FIG. 7, the controller 603 of the measurementprocessing device 601 automatically recognizes presence or absence ofthe irregularity by creating a graph of the cut width as shown in FIG.16. If any irregularity is found, that is, if it is determined that thefilm residues exist, this is notified to the control unit 18. Then, thecontrol unit 18 controls the processing unit 16 to perform the waferprocessing of the process S102 again.

Furthermore, between the first rinsing processing (process S202) and thesecond chemical liquid processing (process S203) in the wafer processingof the process S102, for example, the measurement processing of theprocess S103 may be additionally performed alone or along with theaforementioned wafer processing. Accordingly, the cut width formed bythe first chemical liquid processing (process S201) can be recognizedseparately, and then, the nozzle position can be adjusted based on thisresult. Alternatively, by performing the first chemical liquidprocessing additionally as stated above, the film residues may beremoved.

Second Exemplary Embodiment

In the first exemplary embodiment, the eccentric amount WD is measuredby using the imaging device 270. Based on this eccentric amount WD, itis possible to automatically adjust a holding position of the wafer W.In the second exemplary embodiment, an operation of a case where aholding position adjusting device is provided within the processing unit16 is described.

FIG. 18A and FIG. 18B are diagrams for describing the holding positionadjusting device provided in the processing unit 16 of the presentexemplary embodiment. This device may be provided in a space under theprocessing liquid supply units 250A and 250B shown in FIG. 3, and withinthe housing 260 of the processing unit 16 shown in FIG. 2, for example.

FIG. 18A illustrates the holding position adjusting device 1800 viewedfrom thereabove. Though the wafer W is indicated by a dashed line forthe convenience of illustration, the wafer W is located above theholding position adjusting device 1800.

The holding position adjusting device 1800 includes a hand portion 1801,an arm portion 1802 and a supporting/rotating portion 1803. The handportion 1801 is an arc-shaped supporting member having a size capable ofsurrounding the holding unit 210. Three protruding members 1804configured to be brought into direct contact with the rear surface ofthe wafer W are provided on a surface of the hand portion 1801. Theshape of the hand portion 1801 is not limited to the arc shape as longas it has a curved shape (including an angular shape such as aone-side-opened rectangular shape) having a size capable of surroundingthe holding unit 210.

The arm portion 1802 is connected to one end of the hand portion 1801,and is configured to move the hand portion 1801 horizontally along asingle axis line. The supporting/rotating portion 1803 is connected tothe other end of the arm portion 1802, and is configured to support thearm portion 1802 and rotate, by driving a non-illustrated motor, thehand portion 1801 and the arm portion 1802 as one body in a directionindicated by an arrow 1805. With this configuration, the hand portion1801 can be moved between a position (a state shown by a dashed dottedline in FIG. 18A) where it surrounds the holding unit 210 and a retreatposition (a state shown by a solid line in FIG. 18A). Furthermore, thehand portion 1801 and the arm portion 1802 can also be moved up and downas one body. In FIG. 18A, a dashed double-dotted line indicates theX-axis direction, and the imaging device 270 is also located on thisstraight line, though not shown.

FIG. 18B is a side view illustrating the holding position adjustingdevice 1801 when viewed from the transversal direction. By raising theprotrusion portion 1804 higher than the top surface of the holding unit210, the protrusion portion 1804 can be brought into contact with thewafer while lifting it up, and by lowering the protrusion portion 1804lower than the height of the holding unit 210, the wafer can betransferred onto the holding unit 210. Further, as shown by an arrow,the arm portion 1802 is configured to be linearly moved forwards andbackwards in the X-axis direction. Thus, the position of the arm portion1802 can be changed linearly in the forward/backward direction.

Now, referring to flowcharts of FIG. 19 and FIG. 20, a holding positionadjusting processing according to the present exemplary embodiment willbe explained.

As shown in the overall flow of FIG. 19, the holding position adjustingprocessing according to the present exemplary embodiment is additionallyperformed after the wafer carrying-in processing of the process S101 inthe overall flow of FIG. 7 described in the first exemplary embodiment.In FIG. 19, since the other processings except the holding positionadjusting processing of the process S111 are the same as those describedin FIG. 7, redundant description will be omitted. Below, details of theprocess S111 will be discussed with referent to the flowchart of FIG.20.

Referring to FIG. 20, the first imaging condition is set as the imagingcondition of the imaging device 270 (process S401). Then, the imaging ofthe wafer W under the first imaging condition (process S402), thedetermining of the number of imaging operations (S403) and the rotatingof the wafer W (S404) are repeated as many times as a preset number ofimaging operations. Since these processings are the same as the repeatedprocessings from the process S301 to the process S305 shown in FIG. 12Aand FIG. 12B except the imaging operation (process S303) under thesecond imaging condition, detailed description thereof will be omittedhere. As stated in the first exemplary embodiment, only the position ofthe wafer circumferential edge 1111 is required to know the eccentricamount WD, the imaging is conducted only under the first imagingcondition.

If the above-described operations are finished (process S403: Yes), aprocess S405 is performed, and an image analysis processing is performedby using 360 sets of the first images (S405). Then, the eccentric amountWD is determined as a measurement result (process S406). Since detailsof the image analysis processing for calculating the eccentric amount WDis already described in FIG. 15 according to the first exemplaryembodiment, description thereof will be omitted here. Here, however, itis also stored when the wafer circumferential edge 1111 takes themaximum value and the minimum value. By way of example, if the wafercircumferential edge 1111 has the maximum value at the 60^(th) time ofthe imaging operation and the minimum value at the 240^(th) time of theimaging operation, when the wafer W is placed on the holding unit 210, avector of the eccentric amount WD, that is, a direction of the deviationis oriented toward a direction in which the wafer is rotated −60 degreesfrom the initial rotation position in the process S401.

Subsequently, a process of adjusting (correcting) the position of thewafer W based on the eccentric amount WD is begun. From here, anoperation of the holding position adjusting device 1800 will beexplained with reference to FIG. 21A to FIG. 21H.

First, an operation of adjusting a phase of the eccentricity of thewafer W (S407). If the rotating operation of the holding unit 210 is notperformed from when the 360 times of the imaging operation are ended inthe process S403, the holding unit 210 is located at the initialrotation position of the process S401. In this case, the wafer W isrotated by a rotation angle at which the wafer circumferential edge 1111takes the maximum value. In the aforementioned example, the wafer W isrotated by 60 degrees from the initial rotation position. As a result,the direction of the vector of the eccentric amount WD and the X-axisdirection are made to be coincident, and the holding position adjustingdevice 1800 is capable of adjusting the wafer W to an appropriateposition with a simple control operation of moving the wafer W by theeccentric amount WD in parallel with the X-axis direction.

Thereafter, the cover member 230 (imaging device 270) which is in astate shown in FIG. 21A is moved to the retreat position (position abovethat shown in FIG. 2) by the elevating device 240, and the cup body 220is lowered by the lifter 243 of the cup elevating device (process S408).Here, the holding unit 210 is still attracting and holding the wafer W(as indicated by a white downward arrow).

Afterwards, as depicted in FIG. 21B, by operating the holding positionadjusting device 1801, the arm portion 1802 is advanced into a spacebetween the wafer W and the cup body 220 while being rotated, and thehand portion 1801 is located under the wafer W (S409). Afterwards, theholding unit 210 stops the attraction of the wafer W (S410).

Then, based on the eccentric amount WD determined in the process S406,the position adjustment of the wafer W is performed (S411). First, asshown in FIG. 21C, the supporting/rotating portion 1803 raises the armportion 1802 and brings the protrusion portion 1804 of the hand portion1801 into contact with the rear surface of the wafer W. At this time,the hand portion 1801 supports a region of the rear surface of the waferW outside a region in contact with the holding unit 210, as depicted inFIG. 18A and FIG. 18B. Further, as illustrated in FIG. 21D, the handportion 1801 and the arm portion 1802 are raised, so that the holdingunit 210 is released from the contact with wafer W. Then, as shown inFIG. 21E, the arm portion 1802 is moved as much as the eccentric amountWD.

Thereafter, the arm portion 1802 is lowered, and the wafer W is broughtinto contact with and attracted to the holding unit 210 again (S412), asshown in FIG. 21F. Further, as illustrated in FIG. 21G, by lowering thearm portion 1802 further, the arm portion 1802 is released from thecontact with the wafer W.

Then, as depicted in FIG. 21H, the arm portion 1802 is retreated (S413).Finally, the cover member 230 is lowered by the elevating device 240,and the cup body 220 is moved upward by the lifter 243 of the cupelevating device to return back to the position shown in FIG. 2, so thatthe series of the processings are ended (S414).

As stated above, according to the present exemplary embodiment, there isprovided the holding position adjusting device 1800 configured to adjustthe holding position of the wafer W with respect to the center of theholding unit 210 based on the eccentric amount of the wafer W which isdetermined based on the images obtained by the imaging device 270. Thisholding position adjusting device 1800 adjusts the holding position ofthe wafer W while supporting the wafer W from the rear surface thereof.Since the holding position adjusting device 1800 adjusts the position ofthe wafer W under the wafer W, a space for providing the holdingposition adjusting device within the housing can be reduced, as comparedto a conventional case where the position adjustment of the wafer W isperformed while holding the peripheral end portion of the wafer W andperforming the position adjustment in a transversal direction.Accordingly, the position adjustment can be well performed withoutcausing an increase of a footprint of an apparatus. Furthermore, sincethe wafer W is supported from below by the protrusion members 1804 ofthe hand portion 1801, the position of the wafer W can be appropriatelyadjusted stably without causing damage on the circumferential edgeportion of the wafer W. In addition, since the position adjustment isperformed while supporting the rear surface of the wafer W at the regionoutside the region where the wafer W is in contact with the holding unit210, a sufficient uplift amount can be obtained just by lifting thewafer W slightly apart from the holding unit 210. Thus, it is notnecessary to secure a space in the Z-axis (vertical) direction in orderto perform the position adjustment in the structure of the processingunit 16. Furthermore, since the eccentric direction is specified byrotating the wafer W in advance and the position adjustment is performedafter rotating the wafer W such that the eccentric direction coincideswith the direction (X-axis direction) of the linear movement of the armportion 1802, the holding position adjusting device can be controlledsimply and accurately.

Third Exemplary Embodiment

In the above-described exemplary embodiments, the measurement processingdevice 601 conducts image setting of the imaging device 270 prior tostarting the measurement processing. However, this may be modifieddepending on a wafer as a measurement target or the content of aprocessing involved.

The wafer as a measurement target may be of various kinds. By way ofexample, the wafer may have a water-soluble film or a metal film such astitanium, aluminum or tungsten. Since these films have their ownrefractive indexes or attenuation factors, they exhibit differentreflection characteristics of light. Therefore, even if the imaging isperformed under the same imaging condition by the imaging device, theluminance levels of edges shown on the image may be different.

In the first exemplary embodiment, as the second imaging condition, theimaging condition in which an emphasis is put on a reflection lightlevel of an intermediate illumination level is set to accurately specifythe position of the processing film boundary 1109 in the film structureshown in FIG. 11.

However, the reflection characteristic of light differs on the kind ofthe film. Thus, even with the reflection light level of the intermediateillumination level, there may be a case where an accurate edge detectioncan be performed by allowing an intermediate illumination level at a lowillumination level side to have a wide gradation width, or, to thecontrary, a case where an accurate edge detection can be performed byallowing an intermediate illumination level at a high illumination levelside to have a wide gradation width.

Furthermore, though the round of the wafer W is formed from a basethereof, the reflection characteristic of the light is differed if thematerial of the wafer itself is different. Thus, there may be a casewhere successful detection can be performed by changing the firstimaging condition depending on the kind of the film.

Furthermore, there may also be a case where it is better to change theimaging condition depending on the size of the set cut width even if thekind of the film is same.

In the present exemplary embodiment, a measurement setting, whichincludes the imaging condition and so forth, is defined as “imageprocessing recipe,” and the image processing recipe is selecteddepending on the kind of the film of the wafer as a processing target.Below, the image processing recipe according to the present exemplaryembodiment will be explained with reference to FIG. 22A and FIG. 22B.

FIG. 22A illustrates a table 2201 for the measurement setting showing acorrespondence between a film kind and an image processing recipe. Animage processing recipe 2202 is provided for each film kind 2203 andeach cut width 2204. This list is previously stored in the storage unit607 of the information processing device 602.

In the present exemplary embodiment, the imaging condition included inthe image processing recipe is a condition reflected on brightness ofthe image, and includes setting of CCD sensitivity or setting ofexposure. Further, if details of brightness/darkness of the image arechanged as the size of the set cut width or the imaging condition ischanged, it may be desirable to change an algorithm of the edgedetection processing in correspondence to such a change. Thus, accordingto the present exemplary embodiment, an edge detection method of thedetection processing or a method of a corresponding processing(conversion of gradation, etc.) for the edge detection may be changed.

FIG. 22B illustrates the list of image processing recipes according tothe present exemplary embodiment. The list 2205 of the image processingrecipes is previously stored in the storage unit 604 of the measurementprocessing device 601.

An image processing recipe A is provided for a processing of removingthe peripheral portion of the wafer having thereon the water-solublefilm by a width of 3 mm, and uses the first imaging condition as acondition 2206 for imaging the round region and the second imagingcondition as a condition 2207 for imaging the processing film boundary.Further, a detection processing A is performed as the edge detectionprocessing 2208.

In a processing of removing the peripheral portion of the wafer havingthereon the water-soluble film by a width of 2 mm, a detectionprocessing B and a third imaging condition optimum for detecting anarrow cut width are selected. Further, in case of aluminum or titanium,since both the base and the film of the wafer have differentcharacteristics to light from the wafer having thereon the water-solublefilm, the optimum imaging condition is set, or a condition in which theimage processing and the detection processing can be performed is set.Furthermore, a standard image processing recipe E is also prepared for acase of processing a wafer whose film kind is unknown. By way ofexample, an eighth imaging condition is a condition includingintermediate setting values between the first imaging condition and afourth imaging condition, and a ninth imaging condition is a conditionincluding setting values obtained by averaging the second imagingcondition, the third imaging condition, a fifth imaging condition and asixth imaging condition.

A processing of the present exemplary embodiment is applicable to theimaging setting performed in the process S301 of the flowcharts shown inFIG. 12A and FIG. 12B. Details of the imaging setting according to thepresent exemplary embodiment will be explained with reference to aflowchart of FIG. 23.

First, a wafer processing recipe is specified by receiving from anexternal device or according to a manipulation input from themanipulation device 601. The specified wafer processing recipe is sentfrom the control device 4 to the information processing device 602. Inthe information processing device 602, the controller 606 acquires thewafer processing recipe (S501).

Subsequently, the content of the acquired wafer processing recipe isread out, and information upon the film kind of the wafer W as aprocessing target and the cut width to be etched are specified (S502).

The controller 605 searches, from the selection table of FIG. 22A storedin the storage unit 606, the kind of the film and the cut widthspecified in the process S502. Since there is a set of this film kindand the cut width, a corresponding recipe A is selected (S503).

Then, the information processing device 602 sends, to the measurementprocessing device 601, setting instruction information instructing suchthat the selected recipe A is used. The controller 603 of themeasurement processing device 601 reads out the recipe A from thestorage unit 604 by using the received setting instruction information,and then, sends the imaging condition to the imaging controller 515. Theimaging controller 515 sets the received imaging condition for a nextimaging operation. Further, the controller 603 also sets the detectionprocessing for performing the measurement processing (S504).

So far, an example of the present exemplary embodiment has beendescribed. In case that the information upon the kind of the film is notwritten in the wafer processing recipe in the process S501, theinformation upon the kind of the film may be acquired through adifferent method in the process S502. For example, a non-illustratedsensor configured to detect the film kind by irradiating light to thefilm and receiving reflection light therefrom may be provided within thehousing 260. By inspecting the carried-in wafer W directly, thecontroller 603 may specify the kind of the film of the wafer W.

As stated above, according to the third exemplary embodiment,information upon the kind of the film of the wafer W is previouslyacquired, and a measurement setting corresponding to the kind of thefilm is selected from a multiple number of measurement settingspreviously stored in the storage unit 607. Then, the imaging device 270obtains an image of the peripheral portion of the wafer W by using theselected measurement setting. Thus, a measurement processing can beperformed appropriately and rapidly without troubling the user to adjustthe measurement setting such as the imaging condition.

Fourth Exemplary Embodiment

In a fourth exemplary embodiment, a method of analyzing information uponthe measurement processing result accumulated in the informationprocessing device 601 and utilizing this information for repair andmanagement of the apparatus will be explained.

FIG. 24 illustrates a management list 2400 of the measurement processingresult stored in the storage unit 607 of the information processingdevice 601.

The information of this management list 2400 includes processing recipeinformation 2401 which can be specified from the content of theprocessing recipe to be performed on the wafer W as a processing target;and measurement processing result information 2402 specified whenperforming the measurement with the measurement processing device 601.

The processing recipe information 2401 includes a lot ID 2403 and awafer ID 2404 as identification information of the wafer W. Further, aset cut width 2406, a film kind 2405 related to a specific processingare also included.

The measurement processing result information 2402 includes an imageprocessing recipe 2407 described in the third exemplary embodiment; anda date 2408 and time 2409 when the measurement processing is performedbased on the image processing recipe. Further, as a result of performingthe measurement processing, the measurement result information 2402includes a maximum value “MAX” 2410, a minimum value “Min” 2411 and anaverage value “Ave” 2412 of results of the cut width with respect to 360points. Further, not only the maximum value and the minimum value butall measurement values at the 360 points may also be stored.

The information processing device 601 prepares, in the storage unit 607,a folder for storing the image for the measurement processing of everysingle sheet of wafer W; and a folder for storing the imaging settingsuch as focus adjustment information of the imaging device 270 used whenperforming the imaging. As the measurement processing result information2402, a link 2413 to the folder for the image and a link 2414 to thefolder for the imaging setting information are also stored.

Now, a specific analysis processing and a method of repair andmanagement with the information list of the measurement processingresult will be explained.

As for a lot ID “3342,” the measurement processing is consecutivelyperformed on 25 sheets of wafers W of the same kind by using the samewafer processing recipe and the image processing recipe A. Accordingly,it can be checked whether the wafer group of a single lot iscut-processed uniformly.

As for the lot ID “3342” and a lot ID “3842,” though the same kind ofwafers W are processed by using the same wafer processing recipe and theimage processing recipe A, the measurement processings are performed ondifferent dates. Details of this example will be explained withreference to FIG. 25A and FIG. 25B.

FIG. 25A presents a graph in which a vertical axis represents theeccentric amount ((maximum value “Max”−minimum value “Min”)/2) and ahorizontal axis indicates a date (and time) when a measurementprocessing is performed. The controller 606 of the informationprocessing device 602 is capable of creating this graph based on themanagement list 2400.

This graph shows a change of the eccentric amount with the lapse oftime. In an example of a change 2501 with the lapse of time in FIG. 25A,the eccentric amount is found to increase as time elapses. As one ofreasons for this, it is deemed that the wafers W cannot be transferredaccurately because of abrasion of members constituting the substratetransfer device 17.

The controller 606 of the information processing device 601 creates thegraph of the change 2501 with the lapse of time and sends this graph tothe control device 4. In response to a request from the user orautomatically, the control device 4 displays this graph on the graphwindow 1705 of the display screen 1700 of FIG. 17 described in the firstexemplary embodiment.

Further, an eccentric amount that is allowable in the aspect ofoperating the apparatus may be previously set as a first threshold valuethrough experiment, for example, and if there comes out a result thatthe eccentric amount approaches the first threshold value, this may beautomatically notified to the user. In the example of FIG. 25A, at atime when the eccentric amount exceeds a second threshold value smallerthan the first threshold value, the display screen 1700 is configured tocall user's attention such that the user may check or exchange thesubstrate transfer device 17. Further, it may be also possible toextract plural measurement results of the eccentric amount beforereaching the second threshold value. Investigating whether these pluralvalues has a gradient of increase may be added as a condition ofdetermining whether to call user's attention in addition toinvestigating whether the eccentric amount exceeds the second thresholdvalue.

Further, if the eccentric amount suddenly exceeds the first thresholdvalue as in a change 2502 with the lapse of time, it is highly likelythat the apparatus is abnormal. Thus, an alarm or a notice of stoppingthe apparatus may be given on the display screen 1700.

In a graph of FIG. 25B, a vertical axis represents an absolute value ofa difference between an average value “Ave” which indicates an actualcut width and a set value of the cut width, and a horizontal axisrepresents a date (and time) when a measurement processing is conducted.

This graph shows a change in accuracy of a liquid discharge position bythe processing liquid supply unit 250A (250B) with the lapse of time. Inan example of a change 2503 with the lapse of time in FIG. 25B, theaccuracy of the liquid discharge position is found to decrease as timeelapses. As one of reasons for this, it is deemed that the liquiddischarge position cannot be accurately controlled due to abrasion ofmembers constituting the processing liquid supply unit 250A (250B). Inthis case, as in FIG. 25A, the graph of the change 2403 with the lapseof time may be displayed on the graph window 1705 of the display screen1700 in response to a request from the user or automatically.Furthermore, when the eccentric amount exceeds the second thresholdvalue, user's attention may be called. In addition, as in the example ofFIG. 25A, it may also be added as a condition of determining whether tocall user's attention whether plural absolute values of the differencehas a gradient of increase.

Furthermore, if the eccentric amount suddenly exceeds the firstthreshold value as in a change 2504 with the lapse of time, it is highlylikely that the apparatus is abnormal. Thus, an alarm or a notice ofstopping the apparatus may be given on the display screen 1700.

An overall flow of the system according to the present exemplaryembodiment is shown in FIG. 26. As shown in this figure, a resultanalysis processing of a process S131 is added to the flowchart of FIG.7. Thus, description of the processes S101 to S104 will be omitted here.

Now, details of the result analysis processing of the process S131 willbe explained with reference to a flowchart of FIG. 27.

First, the information processing device 602 acquires the measurementresult information from the measurement processing device 601 (S601).The information acquired here is the measurement processing resultinformation 2402 shown in FIG. 24.

Then, the information acquired in the process S601 is stored in thestorage unit 607, and the management list 2400 shown in FIG. 24 iscreated (S602). Here, since the processing recipe information 2401 isalready acquired before the measurement processing, an operation ofrelating the processing recipe information 2401 and the measurementprocessing result information 2402 is conducted. If a list is alreadycreated, the management list 2400 is updated by adding the currentmeasurement processing result information.

As a processing of analyzing a processed state of a wafer W, it isinvestigated whether an eccentric amount of the single sheet of wafer Was a current measurement result exceeds a preset first threshold value(S603). Here, if it is determined that the eccentric amount exceeds thefirst threshold value (S604: No), an alarm is set off (S605), and, forexample, the apparatus is stopped to cope with abnormality.

Likewise, as a processing of analyzing the processed state of the waferW, it is investigated whether the difference between the actual cutwidth and the set value of the cut width exceeds a first threshold value(S603). If it is found out that the difference exceeds the firstthreshold value (S604: No), an alarm is set off (S605), and, forexample, the apparatus is stopped to cope with abnormality.

Meanwhile, if it is determined that the above value does not exceed thefirst threshold value, an analysis of a change with the lapse of time isconducted (S606) as a processing of analyzing the processed state of thewafer W. Here, as stated above, it is determined whether the eccentricamount or the cut width exceeds a second threshold value, and, if so(S607: No), a notification is made to call user's attention through thedisplay screen 1700 (S608).

If there is no special abnormality, a graph created to notify theanalysis result is displayed on the graph window 1705 of the displayscreen 1700 (S609). The graph may be displayed concurrently with thesetting-off the alarm (S605) or the calling of the user's attention(S608).

As described above, according to the present exemplary embodiment, theinformation processing device 602 creates the management list 2400including the processing recipe information 2401 and the measurementprocessing result information 2402. The processed state of the substrateis analyzed based on this management list 2400, and a presetnotification is made to the user according to the analysis result. Inthis way, by managing the information upon the removal of the film onthe peripheral portion of the wafer W, the processing unit 16 can beoperated stably for a long time. Particularly, a problem or an abradedstate and deteriorated state of the processing liquid supply unit 250 orthe substrate transfer device 17 can be found out from the cut width orthe eccentric amount, and repair or exchange of the members can beconducted at an appropriate timing.

Fifth Exemplary Embodiment

In the first to fourth exemplary embodiments, the measurement processingis performed before or after the chemical liquid processing to acquirethe result of the wafer processing or the eccentric amount.

Meanwhile, it may be required to check a state of the wafer or the likewhile a liquid is actually being supplied. If a state during the liquidsupply can be investigated, this can be reflected in adjusting a supplyamount of a processing liquid or a nozzle position. In a fifth exemplaryembodiment, an example of performing the measurement processing duringthe chemical liquid processing or the rinsing processing will beexplained.

FIG. 28 is a plan view of a processing unit 16 according to the presentexemplary embodiment. In the first to fourth exemplary embodiments, theimaging device 270 is provided between the two processing liquid supplyunits, and a region on the wafer W where no chemical liquid exists isimaged. In the present exemplary embodiment, as illustrated in FIG. 28,an imaging device 270A and an imaging device 270B are provided. Theimaging device 270A is provided in front of the processing liquid supplyunit 250A in the rotational direction R₁ of the wafer W to image a statewhere the processing liquid is supplied. Likewise, the imaging device270B is provided in front of the processing liquid supply unit 2506 inthe rotational direction R₂ of the wafer W to image a state where theprocessing liquid is supplied. Furthermore, since the present exemplaryembodiment is applicable as a part of the overall flow of FIG. 7 or FIG.19 described in the prior exemplary embodiments, at least one of theimaging device 270A and the imaging device 2706 is used to measure thecut width and the eccentric amount. In addition, in the presentexemplary embodiment, it is assumed that an influence of a liquidadhering to or coated on the imaging device upon the imaging operation,which is discussed in the first exemplary embodiment, is negligible.

In a configuration where the imaging devices are disposed as in FIG. 28according to the present exemplary embodiment, imaging ranges of theimaging devices 270A and 270B and a position relationship between awafer W and a liquid thereon will be explained with reference to FIG.29A and FIG. 29B.

In FIG. 29A and FIG. 29B, a region 2901 indicates an imaging range ofthe imaging device 270A, and a region 2902 indicates an imaging range ofthe imaging device 270B.

FIG. 30 is a diagram for describing an arrangement relationship betweenthe imaging device 270, the processing unit 16 and the wafer W and theliquid-existing state of the chemical liquid or the rinse liquid at theregion 2901 or the region 2902.

FIG. 30 shows a state immediately after the chemical liquid processingis begun. In this state, the processing film is not removed, and thechemical liquid 3001 exists on the processing film and the round region.Further, the imaging is performed with an arrival region 902 (905) as acenter of angle of view. Theoretically, the cut width in the waferprocessing recipe and the liquid-existing width of FIG. 30 may be equal,and one purpose of the present exemplary embodiment is to investigatehow much these two widths are equal. For the purpose, a position of aninner end boundary 3002 of the liquid-existing and a change in the statethereof need to be imaged appropriately.

For example, it is expected that the position or the width of the innerend boundary 3002 is changed if the chemical liquid processingprogresses and the processing film is removed. Thus, in the presentexemplary embodiment, by recording a moving image, not by taking a stillimage, a liquid-existing state from the beginning of the liquidprocessing to the end thereof can be investigated.

Further, since a type in which the liquid exists is different dependingon the rotation number or the property of the processing liquid,conditions for recording the moving image are set to be different for afirst chemical liquid and a second chemical liquid. The imagingcondition is set such that the edge detection between the processingfilm and the liquid-existing region can be performed successfully.

Now, the chemical liquid processing performed along with the movingimage recording according to the present exemplary embodiment will beexplained with reference to a flow chart of FIG. 31. In this flowchart,since the processes S201 to S205 are the same as those described in theflowchart of FIG. 8 of the first exemplary embodiment, descriptionthereof will be omitted.

First, prior to starting the supply of the liquid, a moving image of thewafer W is recorded under a first moving image recording condition(S701). Here, the moving image recording condition is set to beoptimized for the chemical liquid for use in the first chemical liquidprocessing and the rinse liquid for use in the first rinsing processing.

Then, the first chemical liquid processing of the process S201 and thefirst rinsing processing of the process S202 are begun. While performingthe processes S201 and S202, the imaging device 270 continues to recordthe moving image under the first moving image recording condition. Inthe meanwhile, the measurement processing device 601 sends the recordedmoving image to the control device 4 in real time, and the controldevice 4 displays the moving image on the first image window 1703 of thedisplay screen 1700, for example.

Thereafter, the recording of the moving image by the imaging device 270is temporarily stopped, and the recorded moving image is sent to theinformation processing device 602. The information processing device 602performs a record processing of the moving image (S702). Details of therecord processing will be described later.

Then, the imaging device 270 resumes recording of the moving image bychanging to a second moving image recording condition (S703).

Then, the second chemical liquid processing of the process S203 and asecond rinsing processing of the process S204 are begun. Whileperforming the processes S203 and S204, the imaging device 270 continuesto record the moving image under the second moving image recordingcondition. In the meanwhile, the recorded moving image is sent to thecontrol device 4 in real time, and the control device 4 displays themoving image on the second image window 1704 of the display screen 1700.

Afterwards, the recording of the moving image by the imaging device 270is temporarily stopped, and the recorded moving image is sent to theinformation processing device 602. The information processing device 602performs a record processing of the moving image (S704). Details of therecord processing will be described later.

Finally, the drying processing of the process S205 is performed, and theseries of chemical liquid processing is ended.

The chemical liquid processing according to the present exemplaryembodiment has been described as above. During the chemical liquidprocessing of the process S201, the wafer W is rotated at a high speed.In case that the wafer W is rotated at 3000 rpm, it is calculated thatthe wafer W is rotated 50 times for 1 second. Theoretically, the arrivalregion 902 (905) of the chemical liquid or the rinse liquid is notchanged with respect to the angle of view. In case that the wafer W iseccentric as described in FIG. 15, a movement that the position of thewafer circumferential edge 1111 of the wafer W is rapidly changed withina “variation width” shown in FIG. 30 is repeated. A general frame ratefor recording the moving image is about 30 fps. Therefore, it isdifficult to accurately image the fluctuating width and observe it. Tosuppress this problem, it is desirable to perform the chemical liquidprocessing of the process S201 after removing the eccentricity byperforming the holding position adjusting processing shown in theprocess S111 of FIG. 19. Further, the holding position adjustingprocessing may not be limited to the method described in the secondexemplary embodiment.

Now, the record processing of the process S702 and the process S704 willbe explained. A liquid-existing width during the processing can bechecked as the user observes the recorded moving image. Besides, it ismore desirable to use this liquid-existing width for the feedback to thesetting and the control of a subsequent chemical liquid processing.

In the present exemplary embodiment, the recorded moving image is storedin the storage unit 607, and an inner end boundary 3002 is added to themeasurement processing result information 2402 of the management list2400 as the measurement processing result of FIG. 24. Accordingly, theset cut width 2406, the average value “Ave” 2412 as the actuallymeasured cut width and the inner end boundary 3002 can be compared forevery wafer. Based on the comparison result, feedback setting such asdetermining an offset value of each nozzle of the processing liquidsupply unit 250A (250B) in a subsequent processing is enabled.

As a method of obtaining the inner end boundary 3002, if theillumination levels of the reflection light of the processing filmregion 1101 and the chemical liquid 3001 are sufficiently different, theinner end boundary 3002 can be obtained by acquiring the luminance edgebetween the processing film region 1101 and the chemical liquid 3001 oneach frame of the moving image. Further, as in FIG. 30, since an outwardliquid flow as indicated by an arrow is generated in a region where thechemical liquid 3001 exists, a difference between consecutive frames maybe calculated, and a position in the diametrical direction where amovement direction or a magnitude of an absolute value of a variationamount of the difference changes greatly may be estimated as the innerend boundary 3002.

Here, an example of the feedback through the information upon theliquid-existing state according to the present exemplary embodiment willbe explained.

Assume that the cut width is set to be 3 mm and the liquid supplyingtime is set to be 30 seconds in the first chemical liquid processing ofthe process S201. In this case, a nozzle is located at a positioncorresponding to the cut width of 3 mm, and the supply of the firstchemical liquid is begun at a preset first flow rate. At this time, byreferring to the management list 2400 later, it is found out that theaverage value “Ave” is 3.1 mm and there is a difference.

In the present exemplary embodiment, since the moving image for 30seconds, which is the liquid supplying time, is stored in relation tothis information, it can be investigated what actually happens on thewafer W.

By way of example, by observing the moving image, the user can find aphenomenon that the processing film on the wafer W is removed to bethinned as the processing proceeds and the first chemical liquid reachesa region of 3.1 mm at an elapsed time of 20 seconds.

With reference to this phenomenon, the user may update the recipe suchthat the nozzle is moved outward by 0.1 mm at the elapsed time of 20seconds, or the amount of the first chemical liquid is reduced at theelapse time of 20 seconds, for example. Accordingly, the processing filmcan be suppressed from being excessively removed, and a result that theaverage value “Ave” is 3.0 mm as in the recipe can be obtained.

Besides the setting by the user, the automatic control by the controldevice 4 is also possible. Assume that the inner end boundary 3002 keepsbeing recorded every 1 second during the liquid supplying time of 30seconds. The information processing device 602 analyzes the managementlist 2400, and if it is determined that the inner end boundary 3002 isdeviated 0.1 mm at the elapsed time of 20 seconds as compared to theinformation recorded so far, the information processing device 602notifies this deviation to the control device 4. In order toautomatically control the nozzle position or the liquid amount in thenext processing of the wafer W, the control device 4 sends aninstruction to the processing unit 16 to move the nozzle positionoutwards by 0.1 mm at the elapsed time of 20 seconds or to reduce theamount of the first chemical liquid at the elapsed time of 20 seconds.Further, the control device 4 may also change the recipe itself as inthe aforementioned case by the user or urging the user to change therecipe through the display device 609.

As described above, according to the present exemplary embodiment, thestate in which the liquid exists on the peripheral portion of the waferW can be investigated while the processing liquid is being supplied.Especially, since the boundary between the processing film and theregion where the liquid exists can be specified, this can be effectivelyutilized as information for feedback setting of the cut width or theliquid amount.

In the above, the first to fifth exemplary embodiments have beendescribed. These exemplary embodiments may also be applicable to specialcircumstances such as when starting-up the system or performing themaintenance as well as when processing the product wafer. Further, thesystem structure may not necessarily be fixed to the housing. Forexample, the imaging device may be prepared as a jig, and each devicemay be configured to be connected to or separated from the system atnecessary timing. Further, though the respective exemplary embodimentscan be implemented individually using the necessary parts of the systemconfigurations described in the first exemplary embodiment, co-use ofconfigurations disclosed in other exemplary embodiments is alsopossible. That is, to achieve a complex goal, the first to fifthexemplary embodiments can be performed in appropriate combinations.

From the foregoing, it will be appreciated that various embodiments ofthe present disclosure have been described herein for purposes ofillustration, and that various modifications may be made withoutdeparting from the scope and spirit of the present disclosure.Accordingly, the various embodiments disclosed herein are not intendedto be limiting. The scope of the inventive concept is defined by thefollowing claims and their equivalents rather than by the detaileddescription of the exemplary embodiments. It shall be understood thatall modifications and embodiments conceived from the meaning and scopeof the claims and their equivalents are included in the scope of theinventive concept.

We claim:
 1. A substrate processing apparatus which performs aprocessing of removing a film on a peripheral portion of a substrate,the substrate processing apparatus comprising: a rotating/holding unitconfigured to hold and rotate the substrate; a first processing liquidsupply unit configured to supply a first processing liquid for removingthe film onto the peripheral portion of the substrate while thesubstrate is being rotated in a first rotational direction by therotating/holding unit; and an imaging unit provided at a position infront of an arrival region of the first processing liquid, which issupplied from the first processing liquid supply unit, on the substratewith respect to the first rotational direction, and configured to imagethe peripheral portion of the substrate.
 2. The substrate processingapparatus of claim 1, further comprising: a second processing liquidsupply unit configured to supply a second processing liquid for removingthe film onto the peripheral portion of the substrate while thesubstrate is being rotated in a second rotational direction opposite tothe first rotational direction by the rotating/holding unit, wherein theimaging unit is provided at a position in front of an arrival region ofthe second processing liquid, which is supplied from the secondprocessing liquid supply unit, on the substrate with respect to thesecond rotational direction and between the first processing liquidsupply unit and the second processing liquid supply unit.
 3. Thesubstrate processing apparatus of claim 1, further comprising: acircular ring-shaped cover member configured to cover the peripheralportion of the substrate held by the rotating/holding unit fromthereabove, wherein the imaging unit is provided by notching a part ofthe cover member.
 4. The substrate processing apparatus of claim 3,wherein a height of a lower end of the imaging unit when provided to thecover member is equal to a height of a bottom surface of the covermember facing the substrate.
 5. The substrate processing apparatus ofclaim 4, wherein a glass window configured to block an entrance of anatmosphere into the imaging unit is provided at a lower end of anopening of the imaging unit through which the substrate is imaged. 6.The substrate processing apparatus of claim 3, wherein the imaging unitincludes an optical guide unit configured to guide an optical image ofthe substrate and an imaging functional unit configured to image theoptical image, and a contour of an entire cross sectional shapecombining the notched cover member and the optical guide unit coincideswith a contour of a cross sectional shape of the cover member.
 7. Thesubstrate processing apparatus of claim 3, wherein an adjusting memberconfigured to perform a focus adjustment is provided at a position on atop surface of the imaging unit and higher than the circular ring-shapedcover member.
 8. The substrate processing apparatus of claim 2, furthercomprising: a circular ring-shaped cover member configured to cover theperipheral portion of the substrate held by the rotating/holding unitfrom thereabove, wherein the imaging unit is provided by notching a partof the cover member.
 9. The substrate processing apparatus of claim 8,wherein a height of a lower end of the imaging unit when provided to thecover member is equal to a height of a bottom surface of the covermember facing the substrate.
 10. The substrate processing apparatus ofclaim 9, wherein a glass window configured to block an entrance of anatmosphere into the imaging unit is provided at a lower end of anopening of the imaging unit through which the substrate is imaged. 11.The substrate processing apparatus of claim 8, wherein the imaging unitincludes an optical guide unit configured to guide an optical image ofthe substrate and an imaging functional unit configured to image theoptical image, and a contour of an entire cross sectional shapecombining the notched cover member and the optical guide unit coincideswith a contour of a cross sectional shape of the cover member.
 12. Thesubstrate processing apparatus of claim 8, wherein an adjusting memberconfigured to perform a focus adjustment is provided at a position on atop surface of the imaging unit and higher than the circular ring-shapedcover member.
 13. A processing method of a substrate processingapparatus including a rotating/holding unit configured to hold androtate a substrate, a first processing liquid supply unit configured tosupply a first processing liquid for removing a film on a peripheralportion of the substrate and an imaging unit provided with an openingfor imaging the peripheral portion of the substrate, the processingmethod comprising: supplying a first processing liquid for removing thefilm onto the peripheral portion of the substrate from the firstprocessing liquid supply unit while the substrate is being rotated in afirst rotational direction by the rotating/holding unit; and imaging theperipheral portion of the substrate by the imaging unit which isprovided in front of an arrival region of the first processing liquid onthe substrate with respect to the first rotational direction, in thesupplying of the first processing liquid.